I really like a very good comeback story of technological innovation, wrestle, failure, and redemption. The invention of the scanning capacitance microscope has all of that.
In 1981, RCA filed a patent for the SCM on behalf of firm researcher James R. Matey. The microscope was an unintentional by-product of the VideoDisc expertise the corporate had been struggling to convey to market for the reason that mid-Nineteen Sixties. RCA anticipated the VideoDisc to seize half of the house video market, however as an alternative it misplaced out in an enormous approach to VHS.
RCA’s James. R. Matey invented the scanning capacitance microscope, which used sensors cannibalized from the corporate’s VideoDisc gamers. Hagley Museum and Library
Regardless of the VideoDisc’s struggles, the underlying expertise held a gem: The exquisitely delicate capacitance sensors used within the VideoDisc gamers have been able to measuring capacitance variations on the size of attofarads (1 × 10-18 farad).
However earlier than engineers and scientists might belief Matey’s concept, they wished an unbiased analysis to substantiate the accuracy of the brand new microscope. Researchers on the Nationwide Institute of Requirements and Expertise obliged. Beginning within the early Nineties, they too cannibalized capacitance sensors from previous VideoDisc gamers and custom-built a sequence of SCMs, such because the one pictured at prime. After NIST’s validation, microscope producers commercialized the SCM, chipmakers adopted them to check built-in circuits, thus opening the door to the subsequent era of semiconductors.
Why the RCA VideoDisc Failed
However no story in regards to the scanning capacitance microscope’s triumph could be full with out some dialogue of the VideoDisc’s failure. In idea, it ought to have thrived: It was a completely researched product that anticipated an vital shopper market. Its playback constancy was superior to over-the-air programming and to magnetic tape. And but it bombed. Why?
The VideoDisc effort had begun within the early Nineteen Sixties, when RCA requested itself, “What comes after coloration TV? What would be the subsequent main shopper electronics system?” The corporate determined that the reply was some kind of system to play prerecorded films and TV reveals via your tv. RCA was removed from alone in pursuing this concept. All the house video techniques underneath growth included a storage medium—movie, magnetic tape, nonmagnetic tape, and vinyl discs of varied measurement and composition—and a tool to play again the audio and video in excessive decision. Along with magnetic strategies, data could possibly be saved utilizing electromechanical, photographic, electron-beam, or optical applied sciences.
RCA VideoDiscs have been simply broken by mud and fingerprints, in order that they have been loaded into the SelectaVision participant inside plastic sleeves.Hagley Museum and Library
By 1964, RCA had settled on VideoDiscs. Like a document album (which the corporate had pioneered), a VideoDisc was a grooved vinyl platter that makes use of a stylus for playback. Not like a document, the VideoDisc carried each audio and video, at a a lot greater density, and the stylus was electrical as an alternative of mechanical. (The VideoDisc is usually confused with the LaserDisc, a house video expertise of that period that used an optical laser.)
RCA known as its discs Capacitance Digital Discs. The VideoDisc participant spun the 30-centimeter disc at a relentless 450 rpm. A metallic stylus traced the depressions and bumps within the disc’s groove by registering variations in capacitance, much like the best way that bringing your finger into contact with a touchscreen causes a detectable change within the display’s capacitance at that time. Stable-state circuitry unscrambled the frequency-modulated video sign encoded within the capacitance variations. These variations have been on the order of femtofarads, and the video sign ran at about 910 megahertz. To get a transparent image, the VideoDisc system required very delicate capacitance sensors to detect these tiny variations at excessive frequency.
Sadly, commercialization took for much longer than anticipated. In 1972, RCA introduced that its VideoDisc would debut the next 12 months, but it surely didn’t materialize. An article in Well-liked Science in February 1977 anticipated regional gross sales by the tip of that 12 months. But it surely wasn’t till March 1981 that the RCA SelectaVision system lastly hit the market. Regardless of heavy promotion, it offered poorly and was pulled from the cabinets in 1984. Ultimately, RCA sank about US $500 million over 20 years to develop the VideoDisc, and it was a complete flop.
How Videotape Vanquished the VideoDisc
What went mistaken? In a phrase: videotape. Magnetic tape, which RCA had rejected, turned out to have better shopper enchantment. Launched in 1976, VHS tapes have been cheaper, had extra titles obtainable for buy or hire, and, importantly, allowed house owners to document their very own packages.
Maybe if the VideoDisc had launched in 1973, it may need had an opportunity. However the expertise had different issues. Fingerprints, mud, and scratches torpedoed early designs that envisioned customers eradicating the discs from sleeves as casually as document albums; as an alternative, the ultimate model stored the discs encased in a plastic shell that was then inserted into the participant.
RCA spent 20 years growing its house video system, however in the long run the SelectaVision misplaced out to VHS and VCRs. Hagley Museum and Library
One other downside was working time. In 1977, VideoDiscs might maintain solely about half-hour of fabric per aspect. That rose to an hour per aspect by the point of product launch, however that also meant that any film over 120 minutes must be unfold over a number of discs. The primary VHS tapes might maintain 120 minutes of video (double that of its fundamental tape competitor, Betamax). And VHS stored extending that lead: By the Nineteen Eighties, VHS had lengthy play (4 hours) and prolonged play (six hours) variations, albeit with noticeable drops in decision high quality.
RCA forecasters additionally badly misinterpret the economics of VideoDisc gamers. Their 1977 value estimate for a VideoDisc participant was $500 (about $2,800 in in the present day’s {dollars}). The primary VHS gamers have been way more costly, starting from $1,000 to $1,400, however by the mid-Nineteen Eighties, their value had dropped to $200 to $400. VHS tapes of main Hollywood movies value about $80—way more than VideoDiscs’ $10 to $18 price ticket—however solely diehard followers really paid the fashionable equal of about $440 to purchase a film on videotape. For everybody else, the Hollywood studios licensed titles to third-party rental firms. Seemingly in a single day, unbiased video outlets, supermarkets, and nationwide chains like Blockbuster have been renting films for a small price. For a quick interval, RCA VideoDiscs shared the cabinets with videotapes, however often solely at unbiased outlets and by no means with as many titles obtainable.
In the meantime, RCA struggled to promote its VideoDisc gamers. The corporate had forecast eventual annual gross sales of 5 to 6 million gamers; its first-year purpose was a extra modest 200,000, and but it offered solely half that quantity. By 1984, RCA realized the VideoDisc would by no means come near 50 p.c market penetration, not to mention profitability, and pulled the plug.
Start of the Scanning Capacitance Microscope
Usually that will be the tip of the story, one other failed enterprise in shopper electronics. However again when RCA scientists first started researching the VideoDisc, there have been no microscopes able to figuring out the tiny variations within the disc that encoded the audio/video sign. The bumps and depressions have been lower than a tenth the dimensions of the groove itself; even essentially the most superior microscopes of the day couldn’t detect options that small.
A manufacturing unit employee inspects an RCA VideoDisc, which encoded the audio and video alerts within the disc’s groove. Hagley Museum and Library
And so RCA’s James Matey developed and patented the scanning capacitance microscope (which he abbreviated SCaM, however others properly shortened to SCM) as a quality-control software for manufacturing the VideoDiscs. 4 years after the primary patent, RCA filed a reissue patent with some corrections and enhancements. In a really readable paper within the March 1985 situation of the Journal of Utilized Physics, Matey and fellow RCA researcher Joseph Blanc defined the brand new expertise. The SCM might detect variations in floor topography on the order of 0.3 nanometers over areas on the order of 0.5 sq. micrometers. RCA delayed publication of this paper till it had shuttered the VideoDisc operation, and so Matey and Blanc concluded their paper, “We’re presently within the technique of adapting [the SCM] for comparable makes use of on different samples.” The brand new use turned out to be within the manufacturing of the subsequent era of semiconductors.
Semiconductor efficiency is dependent upon the distribution of deliberately launched impurities, known as dopants, which change the flexibility of the fabric to conduct electrical energy. Within the early days of semiconductor manufacturing, producers used ion mass spectroscopy and a method known as spreading resistance to measure the dopant distribution in a single dimension.
By the late Nineteen Eighties, built-in circuits had turn into so small that the business wanted a approach to measure the dopants in two dimensions. The SCM, used at the side of an atomic pressure microscope, match the invoice. When the conductive tip of the atomic pressure microscope made contact with a semiconductor floor, it created a small capacitance, on the order of attofarads to femtofarads, relying on the dopant focus. The SCM measured the modifications of the native capacitance and mapped the dopant distributions. However the expertise was nonetheless novel and never but commercially obtainable, so researchers at NIST took up the duty of testing it.
Within the early Nineties, Joseph Kopanski, Jay Marchiando, and David Berning started constructing a sequence of {custom} SCMs on the NIST Semiconductor Electronics Division. They did extra than simply reproduce Matey and Blanc’s outcomes. In addition they supplied the business with fashions and software program for extracting two-dimensional dopant distribution from the capacitance measurements.
NIST’s validation of the SCM led to the business manufacturing of the devices, which in flip led to the event of more-advanced semiconductors—an business that’s orders of magnitude extra vital to the worldwide financial system than a shopper product just like the VideoDisc would ever have been. It’s a basic story of redemption within the historical past of expertise: In the beginning of any new tech venture, nobody actually is aware of what the end result will likely be. Generally, you simply need to preserve going, even via abject failure, and belief that one thing good will emerge on the opposite aspect.
A part of a continuing series taking a look at historic artifacts that embrace the boundless potential of expertise.
An abridged model of this text seems within the October 2025 print situation as “RCA’s VideoDisc Gamble Paid Off in Chips.”
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